Department of Physical Therapy and Motor Rehabilitation, Faculty of Medicine and Health sciences, University of Ghent Ghent, Belgium ; Department of Movement and Sport Sciences, Faculty of Medicine and Health sciences, University of Ghent Ghent, Belgium.
Front Hum Neurosci. 2013 Nov 5;7:726. doi: 10.3389/fnhum.2013.00726. eCollection 2013.
Despite an increasing amount of specific correlation studies between structural and functional connectivity, there is still a need for combined studies, especially in pathological conditions. Impairments of brain white matter (WM) and diffuse axonal injuries are commonly suspected to be responsible for the disconnection hypothesis in traumatic brain injury (TBI) patients. Moreover, our previous research on TBI patients shows a strong relationship between abnormalities in topological organization of brain networks and behavioral deficits. In this study, we combined task-related functional connectivity (using event-related fMRI) with structural connectivity (derived from fiber tractography using diffusion MRI data) estimates in the same participants (17 adults with TBI and 16 controls), allowing for direct comparison between graph metrics of the different imaging modalities. Connectivity matrices were computed covering the switching motor network, which includes the basal ganglia, anterior cingulate cortex/supplementary motor area, and anterior insula/inferior frontal gyrus. The edges constituting this network consisted of the partial correlations between the fMRI time series from each node of the switching motor network. The interregional anatomical connections between the switching-related areas were determined using the fiber tractography results. We found that graph metrics and hubs obtained showed no agreement in both groups. The topological properties of brain functional networks could not be solely accounted for by the properties of the underlying structural networks. However, combining complementary information from both imaging modalities could improve accuracy in prediction of switching performance. Direct comparison between functional task-related and anatomical structural connectivity, presented here for the first time in TBI patients, links two powerful approaches to map the patterns of brain connectivity that may underlie behavioral deficits in brain-injured patients.
尽管越来越多的研究关注结构连接和功能连接之间的特定相关性，但仍需要进行联合研究，尤其是在病理条件下。脑白质（WM）损伤和弥散性轴索损伤通常被认为是创伤性脑损伤（TBI）患者脑连接中断假说的原因。此外，我们之前对 TBI 患者的研究表明，脑网络拓扑组织异常与行为缺陷之间存在很强的关系。在这项研究中，我们在相同的参与者（17 名 TBI 患者和 16 名对照组）中结合了任务相关功能连接（使用事件相关 fMRI）和结构连接（使用扩散 MRI 数据的纤维束追踪得出）的估计，允许在不同成像模式的图度量之间进行直接比较。连接矩阵是在包括基底神经节、前扣带回皮层/辅助运动区和前岛叶/额下回的切换运动网络中计算的，该网络的边缘由切换运动网络中每个节点的 fMRI 时间序列之间的偏相关构成。使用纤维束追踪结果确定了与切换相关区域之间的区域间解剖连接。我们发现，两组的图度量和枢纽都没有一致性。脑功能网络的拓扑特性不能仅由基础结构网络的特性来解释。然而，结合两种成像方式的互补信息可以提高对切换性能预测的准确性。在这里，我们首次在 TBI 患者中直接比较了功能任务相关和解剖结构连接，将两种强大的方法联系起来，以描绘可能导致脑损伤患者行为缺陷的脑连接模式。
